\\[-1.8ex] Soil Heterogeneity & $-$3.009$^{***}$ & $-$2.940$^{***}$ & $-$2.974$^{***}$ & $-$0.044$^{**}$ & $-$0.052$^{**}$ & $-$0.051$^{**}$ \\ 
  & (0.820) & (0.794) & (0.833) & (0.022) & (0.024) & (0.024) \\ 
\\[-1.8ex] 
Observations & 23,423 & 23,146 & 22,949 & 23,416 & 23,146 & 22,954 \\ 
R$^{2}$ & 0.550 & 0.646 & 0.650 & 0.813 & 0.789 & 0.790 \\ 
